Category Archives: Real World Problems

The dinosaurs may have volcanoes to thank for their domination of the planet, at least according to one theory. Most scientists think that a severe bout of volcanic activity 200m years ago may have led to the mass extinction that cleared the way for the dinosaurs’ rise. Now we – with a team of colleagues – have discovered new evidence that strengthens this idea: a global geological “fingerprint” indicating volcanic gases were affecting the whole world at the time of the extinction.

Geologists have previously discovered that the Earth’s crust hosts massive amounts of volcanic rock from the end of the Triassic period, 200m years ago. We know from the fossil record that, at about the same time, a very large proportion of Earth’s species died out, which made space for the remaining dinosaurs (and other species) to flourish. As volcanoes can produce large amounts of carbon dioxide (CO2), it’s possible that the volcanic activity that left these massive lava flows behind also provoked global climate change that led to this mass extinction.

What was missing was evidence that the volcanic activity really had such a worldwide impact. By examining geological records from all over the world, we discovered that large amounts of mercury were released into the atmosphere at around the same time as the extinction. As mercury is also released by volcanoes, this suggests the volcanic eruptions really were severe enough to affect the whole world and potentially cause the mass extinction.

The volcanic rocks cover a huge area, across four present-day continents. They are the remains of a huge episode of heightened volcanic activity that lasted about a million years known as the Central Atlantic Magmatic Province (CAMP).

Previous studies have shown that this volcanism might have occurred in pulses. But we didn’t know how the timing and frequency of these emissions compared to the timing of the extinction event and the subsequent recovery of life. Or whether the volcanoes had a worldwide effect. So we decided to look for a “fingerprint” of the eruptions in the same kind of sediments that record the mass extinction.

Mercury marker

Modern volcanoes emit a large number of gases, most famously sulphur dioxide and CO2, but also trace quantities of the metal mercury. This mercury can stay in the atmosphere for between six months and two years and that means it can be distributed around the world before eventually being deposited in sediments at the bottom of lakes, rivers, and seas.

These same sediments record evidence of bouts of climate change and mass extinction. So, if a sediment layer that records a mass extinction also features unusually high mercury concentrations, we can deduce that volcanic activity likely coincided with (and maybe caused) that extinction.

Working with colleagues from the universities of Exeter and Southampton, we investigated six sedimentary records of the end-Triassic extinction for mercury concentrations. These records were from the UK, Austria, Argentina, Greenland, Canada and Morocco. This spread over four continents and both hemispheres gave us global insight into the impact of volcanic gas emissions during the end-Triassic mass extinction.

Emissions culprit.Shutterstock

Volcanic link

We found that five of the six records showed a large increase in mercury content beginning at the end of the Triassic period, with a distinct spike in mercury at the layer corresponding to the extinction itself. The extinction layer in the Morocco sample also overlaps with the volcanic rocks from the CAMP. This meant we could tie this large emission of mercury into the global atmosphere to a specific volcanic event, even though the eruption was around 200m years ago.

What’s more, this evidence reinforces the conclusion that mercury spikes found elsewhere in the geological record were caused by volcanic activity. We found other mercury peaks between the extinction layer and the layer that marked the start of the Jurassic period, which occurred approximately 100,000 to 200,000 years later. This suggests that multiple episodes of tremendous volcanic activity took place during and immediately after the end-Triassic extinction.

More importantly, we were able to show the elevated mercury emissions matched previously established increases in the amount of CO2 in the atmosphere. This strongly supports the theory that the CO2 emissions thought to cause the end-Triassic extinction came from volcanoes.

This link between increased atmospheric mercury and CO2 at the same time as the end-Triassic extinction offers fundamental insights into some of the factors governing the evolution of life on our planet. And, from a geological point of view, it highlights the potential of mercury to help explain other extinction events in Earth’s history.

Elon Musk, the founder of SpaceX and Tesla, has released new details of his vision to colonise parts of the solar system, including Mars, Jupiter’s moon Europa and Saturn’s moon Enceladus. His gung ho plans – designed to make humans a multi-planetary species in case civilisation collapses – include launching flights to Mars as early as 2023.

First of all, let’s not dismiss Musk as a Silicon Valley daydreamer. He has had tremendous success with rocket launches to space already. His paper proposes several interesting ways of trying to get to Mars and beyond – and he aims to build a “self-sustaining city” on the red planet.

Musk outlining initial plans in 2016.

The idea depends on getting cheaper access to space – the paper says the cost of trips to Mars must be lowered by “five million percent”. An important part of this will be reusable space technology. This is an excellent idea that Musk is already putting into practice with impressive landings of rocket stages back on Earth – undoubtedly a huge technological step.

Making fuel on Mars and stations beyond it is something he also proposes, to make the costs feasible. Experiments towards this are underway, demonstrating that choosing the right propellant is key. The MOXIE experiment on the NASA 2020 rover will investigate whether we can produce oxygen from atmospheric CO2 on Mars. This may be possible. But Musk would like to make methane as well – it would be cheaper and more reusable. This is a tricky reaction which requires a lot of energy.

Yet, so far, it’s all fairly doable. But the plans then get more and more incredible. Musk wants to launch enormous spaceships into orbit around Earth where they will be refuelled several times using boosters launched from the ground while waiting to head to Mars. Each will be designed to take 100 people and Musk wants to launch 1,000 such ships in the space of 40 to 100 years, enabling a million people to leave Earth.

There would also be interplanetary fuel-filling stations on bodies such as Enceladus, Europa and even Saturn’s moon Titan, where there may have been, or may still be, life. Fuel would be produced and stored on these moons. The aim of these would be to enable us to travel deeper into space to places such as the Kuiper belt and the Oort cloud.

The “Red Dragon” capsule is proposed as a potential lander on such missions, using propulsion in combination with other technology rather than parachutes as most Mars missions do. Musk plans to test such a landing on Mars in 2020 with an unmanned mission. But it’s unclear whether it’s doable and the fuel requirements are huge.

Pie in the sky?

There are three hugely important things that Musk misses or dismisses in the paper. Missions such as the ExoMars 2020 rover – and plans to return samples to Earth – will search for signs of life on Mars. And we must await the results before potentially contaminating Mars with humans and their waste. Planetary bodies are covered by “planetary protection” rules to avoid contamination and it’s important for science that all future missions follow them.

Musk inspecting a heat shield at the SpaceX factory.Steve Jurvetson/Flickr, CC BY

Another problem is that Musk dismisses one of the main technical challenges of being on the Martian surface: the temperature. In just two sentences he concludes:

It is a little cold, but we can warm it up. It has a very helpful atmosphere, which, being primarily CO2 with some nitrogen and argon and a few other trace elements, means that we can grow plants on Mars just by compressing the atmosphere.

In reality, the temperature on Mars drops from about 0°C during the day to nearly -120°C at night. Operating in such low temperatures is already extremely difficult for small landers and rovers. In fact, it is an issue that has been solved with heaters in the design for the 300kg ExoMars 2020 rover – but the amount of power required would likely be a show-stopper for a “self-sustaining city”.

Musk doesn’t give any details for how to warm the planet up or compress the atmosphere – each of which are enormous engineering challenges. Previously, science fiction writers have suggested “terraforming” – possibly involving melting its icecaps. This is not only changing the environment forever but would also be challenging in that there is no magnetic field on Mars to help retain the new atmosphere that such manipulation would create. Mars has been losing its atmosphere gradually for 3.8 billion years – which means it would be hard to keep any such warmed-up atmosphere from escaping into space.

The final major problem is that there is no mention of radiation beyond Earth’s magnetic cocoon. The journey to and life on Mars would be vulnerable to potentially fatal cosmic rays from our galaxy and from solar flares. Forecasting for solar flares is in its infancy. With current shielding technology, just a round-trip manned mission to Mars would expose the astronauts to up to four times the advised career limits for astronauts of radiation. It could also harm unmanned spacecraft. Work is underway on predicting space weather and developing better shielding. This would mitigate some of the problems – but we are not there yet.

Europa.NASA

For missions further afield, there are also questions about temperature and radiation in using Europa and Enceladus as filling stations – with no proper engineering studies assessing them. These moons are bathed in the strongest radiation belts in the solar system. What’s more, I’d question whether it is helpful to see these exciting scientific targets, arguably even more likely than Mars to host current life, as “propellant depots”.

The plans for going further to the Kuiper belt and Oort cloud with humans is firmly in the science fiction arena – it is simply too far and we have no infrastructure. In fact, if Musk really wants to create a new home for humans, the moon may be his best bet – it’s closer after all, which would make it much cheaper.

That said, aiming high usually means we will achieve something – and Musk’s latest plans may help pave the way for later exploration.

Scientists have spent decades debating whether asteroids and comets hit the Earth at regular intervals. At the same time, a few studies have found evidence that the large extinction events on Earth – such as the one that wiped out the dinosaurs 66m years ago – repeat themselves every 26m to 30m years. Given that there’s good evidence that an asteroid triggered the dinosaur extinction, it makes sense to ask whether showers of asteroids could be to blame for regular extinction events.

The question is extremely important – if we could prove that this is the case, then we might be able to predict and even prevent asteroids causing mass extinctions in the future. We have tried to find out the answer.

Today, there are approximately 190 impact craters from asteroids and comets on Earth. They range in size from only a few meters to more than 100km across. And they formed anywhere between a few years ago and more than two billion years ago. Only a few, like the famous “Meteor crater” in Arizona, are visible to the untrained eye, but scientists have learned to recognise impact craters even if they are covered by lakes, the ocean or thick layers of sediment.

But have these craters formed as a result of regular asteroid collisions? And if so, why? There have been many suggestions, but most prominently, some scientists have suggested that the sun has a companion star (called “Nemesis”) on a very wide orbit, which approaches the solar system every 26m to 30m years and thereby triggers showers of comets.

Nemesis would be a red/brown dwarf star – a faint type of star – orbiting the sun at a distance of about 1.5 light years. This is not an impossible idea, since the majority of stars actually belong to systems with more than one star. However, despite searching for it for decades, astronomers have failed to observe it, and think they can now exclude its existence.

Difficult dating

Yet, the idea of periodic impacts persists. There are other suggestions. One idea is based on the observation that the sun moves up and down slightly as it orbits the galaxy, crossing the galactic disk every 30m years or so. Some have suggested that this could somehow trigger comet showers.

But is there any evidence that asteroid impacts occur at regular intervals? Most research so far has failed to show this. But that doesn’t mean it isn’t the case – it’s tricky getting the statistics right. There are a lot of variables involved: craters disappear as they age, and some are never found in the first place as they are on the ocean floor. Rocks from some periods are easier to find than from others. And determining the ages of the craters is difficult.

A recent study claimed to have found evidence of periodicity. However, the crater age data it used included many craters with poorly known, or even incorrect and outdated ages. The methods used to determine age – based on radioactive decay or looking at microscopic fossils with known ages – are continuously improved by scientists. Therefore, today, the age of an impact event can be improved significantly from an initial analysis made, say, ten or 20 years ago.

Another problem involves impacts that have near identical ages with exactly the same uncertainty in age: known as “clustered ages”. The age of an impact crater may be, for example, 65.5 ± 0.5m years while another is be 66.1 ± 0.5m years. In this case, both craters might have the same true age of 65.8m years. Such craters have in some instances been produced by impacts of asteroids accompanied by small moons, or by asteroids that broke up in the Earth’s atmosphere.

The Manicouagan crater in Canada seen from the International Space Station/NASA/Chris Hadfield

The double impact craters they produce can make it look like they hit a time when there were lots of asteroid impacts, when actually the craters were formed in the same event. In some cases, clustered impact craters are spaced too far apart to be explained as double impacts. So how could we explain them? The occasional collision of asteroids in the asteroid belt between Mars and Jupiter might trigger short-lived “showers” of asteroids impacting the Earth. Only a few of these showers are necessary to lead to the false impression of periodicity.

Fresh approach

In contrast to previous studies, we restricted our statistical analysis to 22 impact craters with very well defined ages from the past 260m years. In fact, these all have age uncertainties of less than 0.8%. We also accounted for impacts with clustered ages.

Of course, we can’t be sure that there isn’t any periodicity. But the good news is that, as more impact craters are dated with robust ages, the statistical analysis we did can be repeated over and over again – if there is such a pattern, it should become visible at some point.

That means that there is presently no way to predict when a large asteroid collision may once again threaten life on Earth. But then when it comes to facing the apocalypse, maybe not knowing is not so bad after all …

If you look at the scientific literature you might think that most of the work that is reported is theoretical in nature. It depends, of course, how you define theoretical but you would probably be right. And the scientific community makes no apologies for this as, by its nature, it is what they do.

However, there is a need for practitioners to report their results and experiences in the scientific literature so that the community is aware of real world applications and what is happening outside of the theoretical world that many academics occupy.

The benefits of publishing in the scientific literature include the following:

It gets your message out there, so that others might benefit from it.

It places a marker in the sand, that indicates that you reported this work before anybody else (in a scientific sense).

You might be able to use the scientific paper in your marketing material to show that the approaches you are using have been validated by the scientific community.

It might enable engagement with the scientific community which might improve your systems even more.

It might prompt interest from the media who regularly look at what is being published in the hope of getting a story.

The barriers to industrialists publishing in the scientific literature include:

You may not know what the scientific literature is, let alone how to access it.

You simply don’t have enough time, or maybe even the motivation, to write a scientific paper.

Even if you are able to read at a scientific paper, it might not be obvious how to go about writing one.

If you have an idea for a paper, how do you go about getting it published, after you have written it?

Of the thousands of journals out there, how do you choose which one to target?

If you submit a paper to a journal what do you do if you get critical reviewer comments or, even worse, the paper is rejected?

So, how can the industrial community write scientific papers, and be better represented in the scientific literature?

Here are just a few ways that might work for you:

Respond to this post if you are interested in accessing the scientific literature. There might be people reading this forum who would be willing to work with you to help get your work published.

Google (other search engines are available) your idea and see if anything comes up which is associated with a university. Then try contacting the academic who seems to be involved in that project.

Take a look at Google Scholar (as opposed to just Google). This just searches scientific papers and you might find an academic who has expertise in your area of interest.

Most universities have a Business Engagement department. Try contacting them.

The MISTA conference series is interested in seeing more papers and presentations that describe real world problems, and solutions to those problems. If you are interested in discussing such a paper, please feel free to contact one to the conference chairs. The worst they can say is that the suggestion is not suitable for MISTA.

Writing a scientific paper for the first time can be daunting (in fact it is!) but it could be just what your company needs to promote itself to a wider community that you probably don’t have access to otherwise. And, if you need help and advice, then there are plenty of people around who would be more than happy to assist.